Hi, A quick answer that is worth what it's worth for I'm little by little entering OSG myself... For what I know the trackballManipulator hasn't the aim of making the view always look at the same location. The setNode() method() after examination only recomputes 'center' "distanc" and so on paremeters of the "home position", taking into account the contenu of the passed Node's subgraph. The "home position" is only a reference position the camera goes back to upon a hom() call in the code or a pression on the space bar by the viewer user.
I don't know if in the module osgGa ther is a manipulator xhose aim is to always look at the central location of a given object. Regarding the right parameters to use to position the camera, it's the view matrix. The best is to present to your user the content of that matrix (maybe presented in a more "sexy" fashion thant just a 4x4 matrix, I don't knox, the translation in the matrix, the rotation, etc.) It can be achieved from your mainloop via osgViewer::getCamera()->getViewMatrix(), or osgGA::TrackballManipulator::getMatrix(). The manipulator can afterwards be re-set in that position by a call to setByMatrix() or setHomePosition() + home()... Hope that helps... -- Christophe Médard Société OKTAL (http://www.oktal.fr) 2 impasse Boudeville 31100 Toulouse (France) Tél. : (+33) 5 62 11 50 10 Fax : (+33) 5 62 11 50 29 ----- Original Message ----- From: "Poirier, Guillaume" <[EMAIL PROTECTED]> To: "OpenSceneGraph Users" <[email protected]> Sent: Wednesday, September 26, 2007 9:56 PM Subject: Re: [osg-users] Trackball and view question Hi Robert et al. Let me explain what I want to do accomplish an example: I load a model with no camera manipulator. I know the camera parameters (eye, ctr, up) that yield a desired pose. I set the viewer camera with those parameters and obtain the desired pose. Now I want to assume that I don't know those parameters. A user loads a model with a trackball manipulator. He / she can manipulate the model until the desired pose is obtained and recuperate the camera parameters (eye, ctr, up), which should be what I used in the previous step... Is that more clear ? How would I achieve this ? regards, Bill _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
